JPH0311489B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is an improvement in a method for extrusion coating a stranded wire formed by twisting a plurality of highly rigid wires, such as a steel wire armored cable. It is related to.

(Prior art) Twisted wire formed by twisting together hard and difficult-to-stretch strands where untwisting occurs when coating is applied to the stranded wire, causing the coating to swell or twist, causing wrinkles and causing abnormalities in the coating state. A wire, for example, a stranded wire in which all the strands are made of iron wire, or a stranded wire made of hard aluminum wire or hard copper wire with an outer diameter of 1.6 mm or more, and this strand is 19
Stranded wires formed by twisting into multiple layers of more than 1000 strands are untwisted when they are fed out from the supply bobbin, so in order to prevent this untwisting, the wires are placed in front of the extruder and at the back of the cooling tank. Track devices were placed in each, and stranded wires were stretched between the track devices. The endless track device behind the cooling tank also serves as a pulling machine. However, this conventional technology requires two track devices and requires highly rigid lead wires to prevent untwisting of the stranded wires before coating, which increases equipment costs. It is expensive, and because the distance between the two endless track devices is large, untwisting cannot be sufficiently prevented.

(Objective of the Invention) An object of the present invention is to provide a method for coating stranded wires, which allows coating work to be performed while reliably preventing untwisting using simple equipment.

(Structure of the Invention) The stranded wire coating method of the present invention involves coating the coated wire fed out from the extruder when the stranded wire formed by twisting a plurality of wires is passed through an extruder and coated by extrusion. The present invention is characterized in that the coated wire is hardened slightly and then the coated wire is hardened while being pulled through an untwisting prevention means consisting of a clamp that is rotationally biased in the twisting direction while holding the coated wire.

According to this method, there is no need for a track device in front of the extruder, and the take-up machine can be an inexpensive wheel type instead of a track type, resulting in low equipment costs and The prevention means prevents untwisting by twisting the coating immediately after extrusion coating and after the coating has cooled slightly, so that untwisting can be reliably prevented without damaging the coating.

(Embodiment) An embodiment of the present invention will be described in detail with reference to the drawings. FIG. The wire 12 is coated with a resin such as polyvinyl chloride in an extruder 14 to become a coated wire 13, and the coated wire 13 is partially cooled with the coating 13a (see FIG. 2) slightly cooled in the first water tank portion 16A. hardened.

The coated wire 13 whose coating 13a has been slightly hardened in this manner is prevented from untwisting by the untwisting prevention means 18, and the coated wire 13 is transferred to the second water tank portion 16B.
a is completely cooled and hardened, and is wound onto a winding drum 22 while being taken up by a take-up machine 20.
When starting the coating work, a lead wire is connected to the tip of the stranded wire 12, and the stranded wire can be taken out while twisting the lead wire. Note that this lead wire does not need to be particularly rigid.

The anti-untwisting means 18 are shown in detail in FIG.
This untwisting prevention means 18 is connected to a clamp 24 which is rotated and biased in the direction of twisting the coated wire 13 while gripping the coated wire 13.
It consists of In the illustrated embodiment, clamp 2
4 is a track type one, and this clamp 2
Normally, the wires 4 are urged to close together as shown by the solid line in FIG. 2, and when the covered wire 13 passes between them, they are pushed apart as shown by the dotted line. This clamp 24 is supported by a rotating frame 26, and this rotating frame 26 is given a rotational force via a motor 28 and a powder clutch 30 in a direction (in the direction of the arrow) that twists the coated wire 13. In addition, in the above example,
The clamp 24 was of an endless track type, but
It may be composed of three rubber rollers arranged at the vertices of an inverted triangle, and the lower central rubber roller may be biased upward by a coil spring to clamp the covered wire 13.

(Effects of the Invention) According to the present invention, as described above, there is no need for an endless track device in front of the extruder, and the take-up machine can be an inexpensive wheel type instead of an endless track type. Moreover, the equipment cost is low because the lead wire does not need to be rigid at the time of extraction, and the untwisting prevention means is twisted immediately after the extrusion coating and after the coating has cooled slightly to prevent untwisting. This has the practical benefit of being able to reliably prevent untwisting without damaging the coating.

[Brief explanation of the drawing]

FIG. 1 is a schematic system diagram of an apparatus for implementing the stranded wire coating method according to the present invention, and FIG. 2 is an enlarged side view of the untwisting prevention means used in the present invention. 12... Twisted wire, 13... Covered wire, 14... Extruder, 16A, 16B... First and second water tank parts, 18... Untwisting prevention means, 20... Taking machine, 2
4...Clamp, 28...Motor, 30...Powder clutch.

Claims (1)

[Claims] 1. A stranded wire coating method in which a stranded wire formed by twisting a plurality of wires is passed through an extruder and coated by extrusion, in which the coating of the coated wire fed out from the extruder is slightly reduced. After curing the coated wire, the coating is cured while the coated wire is taken through an untwist prevention means consisting of a clamp that is rotationally biased in the twisting direction while holding the coated wire. Coating method. 2. The stranded wire coating method according to claim 1, wherein the untwisting prevention means comprises a clamp that is rotationally biased in a twisting direction while gripping the coated wire.